特定半胱氨酰和甲硫氨酰残基的氧化还原修饰调节各种途径中的关键酶和信号转导蛋白。这里,我们分析了氧化还原修饰对蛋白质结构的影响筛选RCSB蛋白质数据库中蛋白质的氧化修饰,即蛋白质二硫化物,混合二硫化物与谷胱甘肽,半胱氨酰次磺酸,半胱氨酰S-亚硝基化,和甲硫氨酰亚砜残留物。如果可用,将这些结构与还原状态下的相同蛋白质的结构进行了比较,涉及氧化修饰的预先要求以及修饰的结构后果。总的来说,氧化还原修饰引起的构象变化很小,即在正常波动范围内。一些氧化还原修饰,特别是二硫化物,诱导蛋白质静电特性的改变。对于特定残余物的氧化还原改性,溶剂可及性似乎不是严格的先决条件。我们在敏感残基附近发现了某些其他氨基酸残基的富集,对于二硫化物和次磺酸修饰,例如,组氨酸和酪氨酰残基。这些图案,以及敏感的含硫氨基酸的特定特征,可能有助于氧化还原修饰的预测。
Redox modifications of specific cysteinyl and methionyl residues regulate key enzymes and signal-transducing proteins in various pathways. Here, we analyzed the effect of redox modifications on protein structure screening the RCSB protein data bank for oxidative modifications of proteins, i.e. protein disulfides, mixed disulfides with glutathione, cysteinyl sulfenic acids, cysteinyl S-nitrosylation, and methionyl sulfoxide residues. When available, these structures were compared to the structures of the same proteins in the reduced state with respect to both pre-requirements for the oxidative modifications as well as the structural consequences of the modifications. In general, the conformational changes induced by the redox modification are small, i.e. within the range of normal fluctuations. Some redox modifications, disulfides in particular, induces alterations in the electrostatic properties of the proteins. Solvent accessibility does not seem to be a strict pre-requirement for the redox modification of a particular residue. We identified an enrichment of certain other amino acid residues in the vicinity of the susceptible residues, for disulfide and sulfenic acid modifications, for instance, histidyl and tyrosyl residues. These motifs, as well as the specific features of the susceptible sulfur-containing amino acids, may become helpful for the prediction of redox modifications.